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Interpretation of Blood Pressure in Epidemiological Studies and Clinical Trials
Published in Wilmer W Nichols, Michael F O'Rourke, Elazer R Edelman, Charalambos Vlachopoulos, McDonald's Blood Flow in Arteries, 2022
These points refer to studies where all appropriate precautions are taken for accurate use of noninvasive sphygmomanometry, including positioning of the patients, use of appropriate cuff size etc. (Picone et al., 2017). The reason for random variation in systolic and diastolic values is unknown (Clark et al., 2016). When arterial pressure is measured at the same time in the two arms with identical automated devices, the same problem is seen, with standard deviation in the order of 8.5 mmHg (Figure 17.5 [B]) (Lane et al., 2002).
Trauma Physiology and Metabolism
Published in Ian Greaves, Keith Porter, Jeff Garner, Trauma Care Manual, 2021
Ian Greaves, Keith Porter, Jeff Garner
The mean arterial pressure is the average pressure during the cardiac cycle and approximately equates to the diastolic pressure plus one-third of the pulse pressure. As the blood pressure is the product of the CO and SVR, it is subject to the influence of all the factors that can potentially affect its constituent components.
The Systemic Circulation
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
Arteries are low-resistance conduits of blood with elastic walls that contribute to the Windkessel effect of the aorta. The arterial system is one of low volume but high pressure, permitting rapid distribution and redistribution of the cardiac output to all the different organs of the body. The arteries (with the arterioles) contain approximately 15% of the total blood volume (i.e. 750 mL) at a mean pressure of around 100 mmHg. Arterial pressure is the force exerted per unit area of the arterial wall. Aortic and arterial pressures rise during systole to 120 mmHg and fall to 80 mmHg during diastole. Systolic blood pressure increases when there is (i) an increase in stroke volume; (ii) an increase in ejection velocity (without a change in stroke volume); (iii) a decrease in aortic or arterial distensibility; and (iv) an increase in diastolic pressure of the previous pulse. Diastolic pressure increases when there is: (i) a decrease in ejection velocity; (ii) an increase in aortic or arterial distensibility; and (iii) an increase in total peripheral resistance.Arterial pulse pressure is the difference between systolic and diastolic pressures:
Qiqilian ameliorates vascular endothelial dysfunction by inhibiting NLRP3-ASC inflammasome activation in vivo and in vitro
Published in Pharmaceutical Biology, 2023
Yuan Luo, Zhenyuan Tan, Yun Ye, Xiaocong Ma, Guihua Yue
Hypertension is a prevalent cardiovascular disease. Globally, the number of patients with hypertension aged 30–79 has doubled to 1.28 billion since 1990 (NCD-RisC 2021). In patients with hypertension, the continuous increase in arterial pressure damages the blood vessels and impairs the function of many target organs, including the heart, kidneys, and brain, eventually increasing the risk of diseases such as cardiac hypertrophy, cerebral hemorrhage, and atherosclerosis. High blood pressure causes a longer disease course and substantial harm, making it a leading cause of premature death worldwide. The vascular endothelium is the largest endocrine and paracrine organ with crucial and diverse physiological functions. The dysfunction of vascular endothelium owing to organic damage may result in the onset and progression of hypertension. Furthermore, hypertension can cause endothelial damage, thus creating a vicious cycle. Vascular remodelling refers to the adaptive functional and structural alterations that occur in blood vessels in response to the changes in the internal and external environment (Baumbach and Heistad 1989). Vascular remodeling-related disease is regulated by the renin–angiotensin system, inflammatory response, and redox regulation (Whiteford et al. 2016). As a chronic inflammatory condition, the onset and progression of hypertension are also associated with immune hyperactivation and the release of inflammatory mediators in vivo (Vanhoutte et al. 2009).
Presenting features and outcomes of cranial-limited and large-vessel giant cell arteritis: a retrospective cohort study
Published in Scandinavian Journal of Rheumatology, 2022
A Tomelleri, C Campochiaro, S Sartorelli, N Farina, E Baldissera, L Dagna
Medical records of all study participants were retrospectively reviewed. Demographic and clinical features of LV- and C-GCA patients at diagnosis and during follow-up were compared. Specifically, the following clinical features were evaluated: sex, age at diagnosis, diagnostic delay, main pre-existing comorbidities, symptoms and laboratory findings at disease onset, medical treatment, disease outcomes (e.g., number of relapses, cumulative steroid dose, use of steroid-sparing agents, development of aneurysms), and treatment-related complications (e.g., osteoporotic bone fractures, arterial hypertension, diabetes, severe infections). GCA relapse was defined as a presence of symptoms or clinical or radiological signs suggestive of GCA, with or without an increase in inflammatory markers, which resolved upon treatment modification. Osteoporotic bone fractures were defined as fractures occurring spontaneously or after minimal trauma. Arterial hypertension was defined as an increase in arterial pressure requiring introduction of a new treatment or an increase in the patient’s current anti-hypertensive medication. Diabetes was defined according to the International Diagnostic Criteria (21). Severe infections were defined as infectious episodes requiring hospitalization.
Understanding and managing autonomic dysfunction in persons with multiple sclerosis
Published in Expert Review of Neurotherapeutics, 2021
Ivan Adamec, Magdalena Krbot Skorić, Mario Habek
Cardiovascular AD is commonly present in pwMS and can be detected even in the early stages of the disease, the clinically isolated syndrome [10,11]. During the course of the disease, it is observed in up to two thirds of patients [12]. The most common clinical presentation is orthostatic intolerance with symptoms such as dizziness, lightheadedness, blurred vision, and general weakness that typically occur in the upright position and subside in the lying position [13]. These symptoms occur in pwMS as a result of impaired sympathetic vasoconstrictory reflex, which function is to maintain adequate blood pressure during postural change [14]. With the failure of this reflex orthostatic hypotension (OH) occurs defined as a drop in blood pressure of ≥ 20 mmHg systolic and/or 10 mmHg diastolic on orthostatic challenge [15]. The decrease in arterial pressure leads to cerebral hypoperfusion resulting in above mentioned symptoms. OH was found to be present in 15% of patients in a population of 112 people with relapsing remitting MS [13].